Refrigerating apparatus



Dec. 11, 1934. D. E. MACABEE 1,983,766

REFRIGERATING APPARATUS Original Filed March 50, 1929 @ateniert Dee. M, 1934 NEE STAS re atta ATM REFRIGERATING APPARATUS David E. Maccabee, Dayton, Ohio, assignor to Frigidaire Corporation, Dayton, Ohio, a corporation of Delaware Application March 30,

1929, Serial No. 351,361

Renewed January 17, 1934 13 Claims.

cut temperatures.

It is one of the objects of the invention to provide a simplified and economical refrigerating system particularly adapted to soda fountains.

Another object of the invention is to provide an improved and simplified arrangement for maintaining a number of different temperatures by means of a single refrigerating system.

More specifically it is one of the objects of the invention to operate a plurality of evaporating elements in series and to provide an improved and simplified means for controlling the amount of liquid refrigerant which flows thru the series.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing, wherein a preferred form of the present invention is clearly shown.

In the drawing:

.Fig. 1 is a diagram of a refrigerating system embodying the present invention; and

Fig. 2 is a vertical longitudinal section of a portion of a control device.

It is usual to provide soda fountains with a compartment for storing ice cream which should be kept at a temperature of 7 F. or less, a compartment for storing and cooling water on draft which should be maintained at a temperature between 35 and 40 and a compartment for containers of fountain syrups, fruit juices and the like, commonly called a syrup rail, which should be maintained at a temperature between 35 and F.

My invention is concerned with an improved arrangement and method for maintaining the above mentioned compartments at their individual proper temperatures by means of a single refrigerating system or apparatus.

Referring to Fig. 1 any suitable soda fountain is provided with an ice cream storage compartment 11, a water cooling compartment 12 and a syrup rail 13 for holding syrup containers. Each of the compartments may be suitably insulated according to the temperatures at which it is to be maintained. A relatively high pressure evaporator 16 is placed in the water compartment and a relatively low pressure evaporator 1'7 placed in the ice cream compartment. Preferably the evaporator 17 is immersed in a non-freezing solution such as brine as is usual in cases of this character, and the evaporator 16 is immersed in fresh water. These evaporators are preferably of the flooded type and each includes a header 20 forming a reservoir for liquid refrigerant which is kept at a constant level therein under the control of a float 22, and refrigerant circulating tubes or coils 23. The evaporators are supplied with liquid refrigerant through liquid lines 26 and 27 connected in parallel to a condensing element generally denoted by 28 which also withdraws evaporated refrigerant from both said evaporators through a vapor conduit 29.

Refrigerant evaporated in the evaporator 16 is withdrawn through a conduit 30 which is ultimately connected to the conduit 29 and which is provided with any suitable pressure regulating shut-off valve 31, the construction of which may be, for example as is illustrated and described in the application of Gilbert H. Williams, Serial No. 351,363, filed March 30, 1929. This valve is opened by the pressure of refrigerant in the evaporator 16 and automatically closes at some predetermined low pressure corresponding, for example, to 25 F. and thus prevents refrigeration of the evaporator below that temperature.

The condensing element 28 includes any suitable compressor 32 actuated by a motor 33 under the control of a switch 34 which is operated in response to the pressure existing in the vapor conduit 29. When the pressure existing in this conduit is above that corresponding to a temperature of about 5 F. the switch closes to actuate the compressor and withdraw the refrigerant from the evaporator 17 until the pressure has been reduced to a value corresponding to a predetermined low temperature, for example zero degrees. Refrigerant is evaporated in and withdrawn from evaporator 16 only when the pressure regulating valve 31 is open, that is, when the temperature of 16 is above 35 F. The header 20 of evaporator 16 is provided with the usual head or end plate 40, secured to the header in any suitable manner, as by bolts. 41. The head 40 is provided with an inlet 42 and outlet 43 for connection to valves 44 and 45 in the liquid and vapor lines 26 and 80 respectively. Inside the head, and containing the liquid inlet passage 42 is a boss 46 having a small opening 47. A tubular support 48 for the float 22 and a needle valve 50 (controlled by the float) is mounted on the boss 46, and is provided with a bushing 51 registering with the opening 47 and forming a guide for the valve 50.

The support or bracket 48 includes a valve chamber 52 between the end of the passage 47 and the bushing 51. A liquid conduit 54 is attached to the bracket 48 and communicates with this valve chamber. The bracket 48 and valve 50 are disposed below the normal level of liquid in the header 20. A suction tube 55 extends from the outlet 43 into the header, terminating in a horizontal opening 57 above the normal level of liquid in the header. The header normally contains liquid refrigerant to the level 58 and oil to the level 59, at which latter level an oil drain hole 60 is pierced in the tube 55. Thus refrigerant vapor may be withdrawn through the tube 55 from above the level of the liquid and oil may drain out of the header whenever it reaches the level 55.

Connected between the outlet 43 and the vapor conduit valve 45 is a fitting 70 for the connection of a liquid conduit. This fitting includes a body having a reduced shouldered end '71 for insertion into the outlet 43 and an enlarged shouldered opening '12 for receiving the valve 45. Suitable gaskets are provided between the plate 40 and fitting 70 as well as between the fitting and the valve 45 to prevent leaks. The fitting and valve are held in place by bolts '74 which pass through both members and clamp them to the head plate 40. The fitting body '70 has a branch 76 adapted to receive a liquid valve connection '78 as well as the tube 54 which is passed through the outlet tube 55 and outlet 43 and soldered into the branch 76 so as to communicate with the liquid valve connection 78 and to prevent the flow of vapor from the outlet 43 through the branch 76 or liquid from pipe 54 from passing to the compressor. In assembling the apparatus above described a length of flexible copper tubing for the conduit 54 is secured to the branch 76 as shown. The tube is then inserted through the outlet 43 and tube 55 as the fitting '70 is being placed in the outlet 43. Thereafter the tube is suitably bent as shown in Fig. 2 and its other end placed in communication with the valve chamber 52 and attached to the bracket 48 in any desirable manner. It has been found that the connection between the tube 54 and the bracket 48 need not be perfectly liquid tight as will be explained below. After the assembling operation just described the head plate 40 may be bolted to the header.

A conduit 80 connected to the valve '78 leads to an evaporator 81 disposed in the syrup rail 13 above the level of the evaporator 1'7, and preferably including a plurality of horizontal passages 82 and 83. The outlet of the evaporator 81 is connected to the header of the evaporator 1'7 by connection 84.

When the float in the evaporator 17 is down, liquid refrigerant can enter the valve chamber 52 in the float bracket 48 and flow through the conduit 54 to the conduit 80 and thence to the evaporator 81. Since the liquid enters the valve chamber 52 at high velocity due to the high pressure in the condenser, and since the valve chamber and its associated parts are immersed in liquid refrigerant, the velocity head of the entering liquid is converted into pressure head and substantially all of the liquid flows through the tube 54 even though the bushing 51 does not form a liquid tight fit with the needle valve 50. Practically speaking, no appreciable amount of liquid enters the evaporator 17 except through the connection 84. The two evaporators 1'7 and 81, and the float 22 are so inter-related that liquid is admitted to 81 faster than it is ordinarily evaporated there, so that the evaporator 81 mam passes to the evaporator 17 through the connection 84. The header 20 of evaporator 17 forms both a reservoir for liquid refrigerant and a gas and liquid separating chamber. When the compressor,- is operating gaseous refrigerant is withdrawn from the evaporator 1'7 through the connection 60. The float preferably sinks in oil, but floats in the refrigerant, so that whenever the level of liquid refrigerant reaches the point 58 the float closes the valve 50 to prevent more refrigerant from entering the evaporators 81 and 17. As refrigerant is evaporated in 17 and the level reduced, the float permits the valve to open and more refrigerant flows directly to the evaporator 81, part of it being evaporated there and theremainder flowing to the evaporator 17 to be vaporized there.

The above described system provides a very simple and reliable method of cooling the syrup rail of a soda fountain and of controlling the amount of liquid refrigerant which is admitted to the syrup rail evaporator.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. Refrigerating apparatus comprising in combination an evaporator including one or more horizontal passages providing refrigerant evaporating surfaces, a second evaporator below the level of the first mentioned evaporator and including a gas and liquid separating chamber and evaporating surfaces in open communication therewith, means responsive to the level of liquid in the second evaporator for supplying volatile liquid refrigerant to the first evaporator, the evaporating surfaces of the second evaporator being below the liquid level therein, the first evaporator being adapted to evaporate a portion only of such liquid, and means for draining liquid and conducting gaseous refrigerant to the second evaporator.

2. Refrigerating apparatus comprising in combination an evaporator, a second evaporator connected in series with the first mentioned evaporator and including a reservoir for liquid refrigerant, a liquid supply connection attached to the reservoir, a vapor exhaust connection attached to and communicating with the reservoir, a liquid conduit communicating with saidliquid connection and disposed within the reservoir but isolated from the fluid therein, said liquid conduit leaving the reservoir through said vapor exhaust connection and a connecting conduit between said last mentioned conduit and the first mentioned evaporator.

3. Refrigerating apparatus comprising in combination an evaporator including a reservoir for liquid refrigerant, a liquid supply connection attached to the reservoir, a vapor exhaust connection attached to and communicating with the reservoir, and a liquid conduit communicating with said liquid connection and disposed within the reservoir but isolated from the fluid therein, said liquid conduit leaving the reservoir through said vapor exhaust connection, and having its end connected to another member.

4. Refrigerating apparatus comprising in combination an evaporator including a reservoir for liquid refrigerant, a liquid supply connection attached to the reservoir, a vapor exhaust connection attached to and communicating with the reservoir, and a liquid conduit communicating with said liquid connection and disposed within the reservoir but isolated from the fluid therein, said liquid conduit leaving the reservoir through said vapor exhaust connection and having its end connected to another member, and afloat valve disposed in the reservoir for controlling the flow of liquid thru the conduit.

5. Refrigerating apparatus comprising in combination an evaporator including a reservoir for liquid refrigerant, a supporting boss within the reservoir, said boss having a passage for liquid refrigerant therein, a float supporting bracket secured to the boss and having a valve chamber therein, said valve chamber communicating with said passage, a bushing for supporting a valve stem secured to the bracket adjacent the valve chamber, a valve in the chamber having a stem projecting into the reservoir thru said bushing, a float supported on the .bracket for operating said valve and maintaining a liquid level above said bracket, a vapor exhaust connection for said reservoir and a conduit for liquid refrigerant connected to the valve chamber and disposed within said vapor exhaust connection.

6. Refrigerating apparatus comprising in combination an evaporator including a reservoir for liquid refrigerant, a supporting boss within the reservoir, said boss having a passage for liquid refrigerant therein, a float supporting bracket secured to the boss and having a valve chamber therein, said valve chamber communicating with said passage, a bushing for supporting a valve stem secured to the bracket adjacent the valve chamber, a valve in the chamber and having a stem projecting into the reservoir thru the bushing, a float supported on the bracket for operating said valve and maintaining a liquid level above said bracket, a vapor exhaust connection for said reservoir, a conduit for liquid refrigerant connected to the valve chamber and disposed within said vapor exhaust connection, an evaporator connected in series with the liquid conduit, and a connection between the outlet of said evaporator and said reservoir.

'7. Refrigerating apparatus comprising in combination a soda fountain including a storage compartment and a syrup rail, a first evaporator for cooling the syrup rail, a second evaporator connected in series with the evaporator cooling the syrup rail, said second evaporator cooling the storage compartment, said second evaporator including a reservoir for liquid refrigerant, and means for controlling the flow of liquid refrigerant to the syrup rail evaporator in response to the level of liquid in said reservoir including a liquid inlet conduit for said first evaporator passing through said reservoir but isolated from the fiuid therein.

8. Refrigerating apparatus comprising in combination a soda fountain including an ice cream compartment and a syrup rail, a first evaporator for cooling the syrup rail, a second evaporator connected in series with the evaporator cooling the syrup rail, said second evaporator cooling the ice cream compartment, said second evaporator including a reservoir for liquid refrigerant and means for controlling the flow of liquid refrigerant to the syrup'rail evaporator in response to the level of liquid in said reservoir- 9. Refrigerating apparatus comprising in combination a gas and liquid separating chamber; means for maintaining a substantially constant level of liquid therein including an orifice below the level to be maintained for admitting liquid refrigerant from a high pressure source, a valve within the chamber for controlling the flow of liquid refrigerant through the orifice, said valve having a shank, and a guide for the shank, said guide forming a restricted passage from the orifice to the main portion of the chamber; and means for delivering liquid refrigerant from the orifice including a conduit having a portion within the chamber connected between the oriflce and the guide whereby some of the refrigerant flowing from the orifice will flow through said conduit.

10. Refrigerating apparatus comprising in combination a gas and liquid separating chamber; means for maintaining a substantially constant level of liquid therein including an orifice below the level to be maintained for admitting liquid refrigerant from a high pressure source, a valve within the chamber for controlling the flow of liquid refrigerant through the orifice, said valve having a relatively long shank, and a relatively long guide surrounding the shank, and means for delivering liquid refrigerant from the chamber including a conduit having a portion within the chamber connected between the orifice and the guide whereby some of the refrigerant flowing from the orifice will flow through said conduit.

11. A refrigerating system comprising a plurality of compartments to be kept cool, an evaporator in one of said compartments, said evaporator having its parts in open communication, means for automatically delivering and controlling the fiow of liquid refrigerant directly and indirectly thereto, a second evaporator in another of the compartments to be kept cool, means for delivering liquid refrigerant thereto and for preventing the passage of vaporized refrigerant thereto, said automatic means also controlling the flow of liquid through the last mentioned means.

12. A soda' fountain provided with an ice cream storage compartment, a water cooling means, and a syrup rail, a first evaporator for cooling the syrup rail, a second and a third evaporator for the ice cream storage compartment and the water cooling means, one of said last mentioned evaporators being provided with a liquid reservoir connected to the first evaporator, means separated from the liquid in said reservoir for supplying liquid refrigerant to the first evaporator, and means responsive-to the level of liquid within the reservoir for controlling the flow of liquid refrigerant to the first evaporator.

13. Refrigerating apparatus including a plurality of compartments to be kept cool, a refrigerating system for cooling said compartments including a first evaporator in oneof said compartments and a second evaporator in another of said compartments, said second evaporator being provided with a liquid refrigerant container connected to the first evaporator, means separated from the refrigerant in said container for supplying liquid refrigerant to the first evaporator, and means responsive to the level of liquid refrigerant in the container for controlling the supply of liquid refrigerant to the first evaporator.

, DAVID E. MACCABEE. 

